What Causes Foul Smelling Vaginal Discharge Post Unprotected Sex?

I m in my late teens and I m sexually active. Recently I just got tested for HPV/HIV, gonnorhea, and claymydia. I was hPV and HIV free, however I am waiting on my latter results. I have been experiencing a strange smell with my vaginal discharge. It smells almost like urine. I don t normally smell. Nor do I have so much discharge on my underwear. The discharge has been so much i have to change my underwear in the day. It is almost watery and clear. It does, sometimes, have a tint of yellow-green . Hard to explain. I don t experience any pain on my body. Before experiencing all of this, I did have unprotected sex. It was with another girl, though. I am really worried about my body. Normally I don t have this problem. I also do not know how to get treated since I do not tell my parents about my sexual life.